Investigate Wichita Falls Water, NDMA and Potential Public Health Concerns

Visit wfndmadpr.com for source documents, research and the full historical timeline.

While reviewing historical water records for Wichita Falls, I found multiple records involving N-nitrosodimethylamine, or NDMA, a chemical studied because of its potential cancer risk.

NDMA can enter water from industrial sources, but it can also form unintentionally during water and wastewater treatment. One recognized pathway involves chloramination, a disinfection process that combines chlorine and ammonia when certain precursor compounds are present. Many NDMA precursors can be associated with wastewater.

That matters in Wichita Falls because the City has a history of potable reuse for more than a decade.

From July 2014 through July 2015, Wichita Falls operated an emergency direct potable reuse, or DPR, system. Treated wastewater was further treated and returned directly to the drinking-water treatment process.

In January 2018, Wichita Falls began operating a permanent indirect potable reuse, or IPR, system. Today, treated wastewater from the Resource Recovery Facility is sent to Lake Arrowhead, where it mixes with the lake supply before later being withdrawn and treated as drinking water.

The current IPR system is different from the former DPR system. It needs to be evaluated based on how it operates today.

Why current investigation is warranted
Two questions in the public record can be addressed through current testing and engineering review.

1. Chloramination continued after DPR ended
When the temporary DPR system was decommissioned in July 2015, TCEQ documented that Wichita Falls would continue using surface-water treatment plants where chlorine and ammonia are added.

That process creates chloramines.

Chloramination is a recognized pathway for NDMA formation when appropriate precursor chemicals are present. Municipal wastewater can contain NDMA and NDMA precursors.

The question is straightforward:

Are NDMA or NDMA precursors entering the current reuse and drinking-water system, and are current treatment conditions allowing NDMA to form at concentrations that warrant health concern?

Current sampling can help answer that.

2. The current backup IPR system has no identified NDMA treatment barrier
Wichita Falls currently maintains an indirect potable reuse system as a backup water supply. When it is operating, treated wastewater is discharged to Lake Arrowhead and can later return through the City’s drinking-water treatment system.

The current treatment train does not include UV treatment or advanced oxidation as an NDMA treatment barrier. The records reviewed also have not identified routine or recurring NDMA monitoring associated with operation of the backup IPR system.

There is another significant monitoring issue: the public is not routinely notified when the backup IPR system is placed into operation. As a result, residents cannot determine from public notifications when reclaimed wastewater is being introduced into Lake Arrowhead or identify periods when NDMA sampling would be most informative.

Lake Arrowhead provides environmental buffering that was not present during the former direct potable reuse project. However, environmental buffering does not establish whether NDMA is absent or at what concentration it may be present.

Current NDMA sampling should include periods when the backup IPR system is operating, with samples collected from the reclaimed-water stream entering Lake Arrowhead, Lake Arrowhead/raw-water intake, appropriate treatment points, and finished drinking water. The dates and operating status of the IPR system should be documented with those results.

What we are asking the responsible agencies to do

This petition asks the Texas Commission on Environmental Quality, Texas Department of State Health Services, City of Wichita Falls and CDC/ATSDR to work within their respective areas of authority to evaluate the environmental, treatment and public-health questions raised by the available record.

Texas Commission on Environmental Quality
We ask TCEQ to conduct a technical and regulatory review of the current potable reuse and drinking-water system, including:

• Test current finished drinking water and representative distribution-system locations for NDMA using EPA Method 521 or another validated method capable of measuring NDMA at very low concentrations.
• Evaluate appropriate points throughout the IPR system, including treated wastewater before discharge to Lake Arrowhead, source water associated with the drinking-water intake, finished water after treatment and representative distribution-system locations.
• Review treatment and monitoring changes since July 2015, including UV modifications, treatment approvals or exceptions, UV dose requirements, advanced oxidation capability and NDMA monitoring requirements.
• Evaluate chloramination in conjunction with the current IPR system, including whether wastewater derived NDMA precursors may be present under current operating conditions.
• Obtain and evaluate the underlying Eurofins laboratory data from the 2015 Garver pilot study, Project No. 15088070, including reported NDMA results from Wichita Falls reverse-osmosis permeate.
• Review available industrial pretreatment and historical non-residential discharger records for the River Road wastewater treatment system to determine whether potential sources of NDMA or NDMA precursors warrant further investigation.
• Publish sampling data, laboratory reports, engineering conclusions and regulatory findings.

Texas Department of State Health Services
The environmental record also deserves evaluation alongside a reported pattern of pediatric brain tumors diagnosed in Wichita Falls during 2017 and 2018.

The existence of several cases does not establish a common cause. Determining whether the pattern warrants further investigation belongs with qualified public-health professionals.

We ask DSHS to: 

• Evaluate the reported pediatric brain-tumor pattern using current guidance for investigating unusual patterns of cancer.
• Work with the Texas Cancer Registry to identify relevant pediatric brain and central nervous system tumor cases among individuals with historical residence in the Wichita Falls water-service area.
• Consider whether the water-service area is an appropriate exposure geography for analysis.
  Review the environmental evidence involving historical NDMA occurrence, potable reuse, treatment conditions and chloramination.
• Determine whether additional environmental sampling, epidemiologic analysis or health assessment is warranted.
• Coordinate with TCEQ and CDC/ATSDR when additional technical expertise is needed.
• Make the agency's methods, conclusions and recommendations public while protecting patient privacy.

City of Wichita Falls
We ask the City to support a transparent and independent review by:

• Cooperating with current NDMA sampling throughout the reuse and drinking-water system.
  Providing records regarding UV treatment, treatment exceptions, advanced oxidation, chemical dosing and monitoring changes since 2015.
• Providing available underlying records associated with the 2015 Garver/Eurofins pilot study.
• Preserving and providing relevant historical industrial pretreatment and non-residential discharger records.
• Cooperating with TCEQ, DSHS and CDC/ATSDR during any technical, environmental or public-health review.
• Publishing complete testing results and relevant supporting information.

CDC and ATSDR
We ask CDC/ATSDR to provide independent technical assistance and environmental-health review where warranted, including:

• Review of the environmental record concerning NDMA and potable reuse.
• Assistance evaluating potential historical exposure pathways.
• Technical assistance with unusual-cancer-pattern analysis.
• Guidance on whether additional environmental sampling, exposure assessment or public-health investigation is appropriate.
• Coordination with Texas agencies so environmental and health information can be evaluated together.

Why this matters
Historical records can tell us what was measured, discussed and decided in the past.

They cannot tell us exactly what is in Wichita Falls drinking water today.

Current testing can.

Current data can establish whether NDMA is detected, where it is detected and at what concentration.

If NDMA is not detected at appropriate reporting limits, that information matters.

If NDMA is detected, the concentration and location can guide appropriate follow-up.

The public-health questions also deserve professional evaluation. Historical gaps may limit what can ultimately be established, but the available cancer information and environmental record should be reviewed together by the agencies equipped to evaluate them.

Wichita Falls continues to rely on potable reuse as part of its long-term water strategy. The answers matter for people drinking the water today and for decisions about how potable reuse systems are designed, monitored and evaluated in the future.

We are asking the appropriate agencies to collect the data, review the record and determine what further action is warranted.

Test the water. Evaluate the system. Review the health concern. Publish the findings.